The Edge of Physics

Anil Ananthaswamy journeyed to Earth’s extremes to bring the world “The Edge of Physics.”

Balloonlaunch Antarctica
Launch of the balloon-borne superconducting spectrometer (BESS), McMurdo, Antarctica, December 2007.

Anil Ananthaswamy traveled to the ends of the earth to bring the world “The Edge of Physics,” a unique new book that juxtaposes extreme science and extreme travel/adventure. Taking readers from the depths of the Earth’s crust to the heights of mountaintop observatories, from the ice of Siberia and Antarctica to the deserts of Chile and South Africa, Ananthaswamy combines conceptual physics with descriptions of scientists working in remote and awe-inspiring locations. His is an ambitious effort to explain the next generation of experiments in cosmology and particle physics, and at the same time “engender feeling about the amazing scientific journey we’re on,” says the author.

While Ananthaswamy—a consulting editor at New Scientist in London—focuses heavily on the science, “The Edge of Physics” (Houghton Mifflin Harcourt) reads like a travel-adventure story or a work of fiction. Maybe that’s because it was written in the wake of a stalled attempt at a novel, or maybe it’s because the far-flung places he visited have an otherworldly quality familiar only to the select few who have experienced them. Either way, the experiments he highlights have potentially profound implications, as they promise to confirm theories that experimenters have thus far failed to verify, and in the process “drag physics out of its theoretical morass,” as Ananthaswamy puts it.

Last week, Failure interviewed Ananthaswamy about the state of physics, his travels, and the challenges of arranging what might be described as a physicist’s dream trip around the world.

What inspired “The Edge of Physics”?

I had been working on a novel set in the mountains of India that had physics and cosmology at its heart. But it was going nowhere. Meanwhile, I kept thinking of travelling to see telescopes on mountaintops. During a conversation with Saul Perlmutter [a physicist at the Lawrence Berkeley National Laboratory] about the state of cosmology, I realized that if I visited not just the summits of mountains but also the bottoms of mines and other remote and extreme environments, I could tell the story of what’s happening in physics, especially cosmology.

What is happening in physics?

Some would say that physics is in crisis. We can only explain about four percent of the universe with the theories at hand. The rest of the cosmos we don’t really understand. Physicists have intriguing names for these mysterious components: dark matter and dark energy. We have known about dark matter—which makes up most of the mass of galaxies—for decades. The discovery of dark energy—the energy of the fabric of space time itself—is about decade old. On top of this, there is the issue of reconciling Einstein’s general theory of relativity with quantum mechanics. One describes the physics of the very large and the other of the very small. But they don’t work well together. Our best bet for combining the two into a theory of quantum gravity is string theory. But string theory is far from being experimentally verified, and some of its implications—such as the existence of extra dimensions and a vast number of other universes—are, for some physicists, hard to stomach. Something has to break this impasse. That’s where the next generation of telescopes, detectors and experiments come in. They are gathering the data that will help separate the theoretical wheat from the chaff. And maybe even point us towards a theory of quantum gravity.

Why are these cutting-edge physics experiments held in some of the most extreme environments on earth?

To get away from either the polluting influences of human populations or the deleterious effects of Earth’s atmosphere, or to escape the “noise” from cosmic rays on the Earth’s surface.

In the case of optical telescopes, dark skies are an absolute necessity and these can only be found far from inhabited regions. The Earth’s atmosphere is also an enemy: the presence of water vapor and the constantly varying thermal properties of air can smudge the light from distant galaxies. It’s best to go to places that are high up (so that you are above lower, denser layers of the atmosphere), and very dry (to minimize the amount of water vapor in the column of air above the telescope).

When it comes to building a neutrino telescope that uses a block of ice as a detecting material, there’s no other place on Earth that has so much ice as Antarctica. Physicists have no choice but to trek to the bottom of the world.

Finally, going deep underground is a necessary evil for experiments that are trying to detect dark matter. On the ground, interactions with cosmic rays can swamp detectors, and the best way to shield experiments from such particles is to establish labs inside abandoned mines. But it’s extremely challenging to build labs inside mines, as they require tens of thousands of tons of equipment, and access is usually limited to a single mine shaft.

What were some of the challenges you faced in making the individual trips a reality?

Each trip posed its own unique challenges. For instance, going to Lake Baikal in Siberia required extensive paperwork for visas and permits, all of which were in Russian; I had to depend on the kindness of the Russian physicists to ensure every form was filled as per regulations. And the travel was daunting: the flight from London to Irkutsk, via Moscow, spanned eight time zones. Upon arrival, I expected to first reach the Lake Baikal Neutrino Telescope’s coastal station, get used to the cold of the Siberian winter, and then venture onto the ice. Instead, I found myself being driven across a frozen lake within hours of landing. I have to admit to being more than a little worried about trundling over the frozen lake in an ancient Russian military jeep.

But going to Antarctica was the most challenging trip. To begin with, I had to be selected by the U.S. National Science Foundation’s Artists and Writers in Antarctica program, which required writing a grant proposal more intimidating than a book proposal. Once selected, I had to get PQed—physically qualified—and get everything from my teeth to my heart cleared for the journey. I was constantly tense that some physical condition might keep me from getting to Antarctica, which would have been a huge loss for the book.

However, the most frustrating hang-up evinced itself at Heathrow Airport, when I attempted to board a flight to Johannesburg [en route to a potential site for the Square Kilometre Array]. The clerk at the check-in counter informed me that because I had run out of [empty] pages in my passport I would not be allowed to enter South Africa, as they required an entire empty page on which to stick a visa upon arrival. The scientists in Johannesburg tried their level best to get me on the plane, but failed. The whole trip—the flight bookings to and within South Africa, the hotel bookings, and all the scheduled meetings—had to be cancelled. Fortunately, the South African scientists were immensely gracious and reworked the trip for a later date.

Of all the places you visited, which one was the most physically uncomfortable and/or dangerous, either for you personally or the scientists working there?

The Russians and Germans working on the Lake Baikal Neutrino Telescope are the toughest bunch I have ever come across. Not only have they managed to build a pioneering experiment with very little money, they endure harsh conditions with none of the comforts that physicists elsewhere take for granted. They have to work in winter in order to use the lake’s frozen surface as a working platform, as they lack the money to buy ships and submersibles, which would allow them to work year round. Amenities are few, the cold severe, and the conditions dangerous. Imagine being miles away from shore on meter-thick ice, below which is about a mile of frigid water. Lake Baikal is massive—more a sea than a lake—and the waters below cause the ice to lurch and heave. And there are cracks everywhere, some covered by snow and big enough for a man to fall through. Despite assurances that there was no danger of disappearing into the water below because the ice was thick and the cracks thin, it scared me to be on the lake at night.

Antarctica was also extremely uncomfortable, especially the South Pole. Due to the peculiar atmospheric conditions, the effective altitude at the South Pole is almost always more than 10,000 feet. Combine that with extreme cold—in summer it’s -30 C to -40 C taking wind chill into account—and you get what is a very difficult environment to walk around in, let alone do the kind of hard, physical labor that is required of those drilling 2.5-kilometer-deep holes in the ice to build the IceCube Neutrino Telescope.

Even more important is the fact that medical help is limited. When I was visiting the South Pole, one physicist lost a quarter of the vision in one eye. He had to be medevaced, first to McMurdo Station and then on to New Zealand, where he was diagnosed with a detached retina. Had the problem progressed to the center of the retina, he would have lost vision in the eye. It’s a reminder of how dangerous Antarctica can be, even without taking account of the risk of falling into a crevasse or getting lost in a blizzard.

Tell me more about the next generation of telescopes and what questions they might help answer.

The next generation of telescopes promise to dwarf just about everything in existence. Within the next decade, expect three major ground-based optical telescopes to come online: the 24.5-meter Giant Magellan Telescope in Chile; the Thirty Meter Telescope, which is being built by those who gave us the Keck telescopes; and the 42-meter European Extremely Large Telescope that will most likely be built in Chile.

As for space telescopes, watch for the successor to the Hubble—the James Webb Space Telescope—to join forces with the above mentioned giants to help us see to the very edge of the visible universe. Space-based telescopes dedicated to the study of dark energy are also in the works, as is the Laser Interferometer Space Antenna (LISA), an extremely sensitive multi-spacecraft gravitational wave detector.

These telescopes and detectors are all going to help answer basic questions confronting cosmology. What is dark energy? Did a process called inflation occur a fraction of a second after the big bang? What was the universe like when inflation occurred? And what is the exact curvature of space time? The latter is a crucial measurement that can either boost string theory or make things extremely difficult for string theorists.

Of all the places you write about, where do you think the next big advances are going to come from?

In December 2009, the Cryogenic Dark Matter Search [Soudan Mine, Minnesota] experiment reported tantalizing results. They may have glimpsed dark matter, though they need much better data to be sure. I believe that in next few years such dark matter experiments will tell us something about the nature of this mysterious component of our universe, because the experiments are getting very big and sensitive. Also, the Large Hadron Collider will be the focus of physics for the next five years or more. It could make or break many theories, depending on what it finds. And of course, there are the telescopes, both ground- and space-based. You never know what they’ll discover. Remember, it was astronomical observations that gave us dark matter and dark energy in the first place.

How might climate change affect the experiments you chronicle in the book?

Climate change is one of the consequences of the pollution we are spewing into the atmosphere. We can ask a broader question: how might pollution affect telescopes and detectors? If Lake Baikal were to be polluted and lose its clarity, it would make watching for neutrinos extremely difficult. Similarly, if we pollute the Earth with radio transmissions from mobile phones, televisions and radios, then we won’t be able to study the distant universe using radio telescopes. The interference from terrestrial sources would completely overwhelm our instruments.

But climate change itself is also threat. Astronomers spend years scouting for the best sites for their telescopes. But as we are seeing at Paranal, Chile, climate change is altering the atmospheric conditions above the telescope. The skies above a given site could get cloudier, or more turbulent, reducing the efficacy of the telescope. These facilities cost hundreds of millions of dollars, so moving to a different site is not an option. Our ability to see clearly and deeply into the universe could be jeopardized.

Did you have a specific goal in mind when you began working on the book?

Yes. Many people attest to feeling overcome by awe at the immensity of the cosmos. There’s a beauty inherent in the pursuit of knowledge that can alter the emotional content of someone’s day, expanding one’s horizons from the narrow, limited view of daily preoccupations to something that is vast and sublime. I think physics is particularly well-suited to bringing about such feelings. Unfortunately, the words “physics,” “particle physics” and “cosmology” deter many from approaching these subjects. My hope is that “The Edge of Physics” will introduce many more people to an extraordinary enterprise: our attempt to understand the very origin of the universe.